content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable.internal.operators;
  
  import static org.junit.Assert.*;
  
  import java.util.List;
  import java.util.concurrent.*;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.Test;
  
  import io.reactivex.common.*;
  import io.reactivex.observable.Maybe;
  import io.reactivex.observable.observers.TestObserver;
  
  public class MaybeFromCallableTest {
      @Test(expected = NullPointerException.class)
      public void fromCallableNull() {
          Maybe.fromCallable(null);
      }
  
      @Test
      public void fromCallable() {
          final AtomicInteger atomicInteger = new AtomicInteger();
  
          Maybe.fromCallable(new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  atomicInteger.incrementAndGet();
                  return null;
              }
          })
              .test()
              .assertResult();
  
          assertEquals(1, atomicInteger.get());
      }
  
      @Test
      public void fromCallableTwice() {
          final AtomicInteger atomicInteger = new AtomicInteger();
  
          Callable<Object> callable = new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  atomicInteger.incrementAndGet();
                  return null;
              }
          };
  
          Maybe.fromCallable(callable)
              .test()
              .assertResult();
  
          assertEquals(1, atomicInteger.get());
  
          Maybe.fromCallable(callable)
              .test()
              .assertResult();
  
          assertEquals(2, atomicInteger.get());
      }
  
      @Test
      public void fromCallableInvokesLazy() {
          final AtomicInteger atomicInteger = new AtomicInteger();
  
          Maybe<Object> completable = Maybe.fromCallable(new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  atomicInteger.incrementAndGet();
                  return null;
              }
          });
  
          assertEquals(0, atomicInteger.get());
  
          completable
              .test()
              .assertResult();
  
          assertEquals(1, atomicInteger.get());
      }
  
      @Test
      public void fromCallableThrows() {
          Maybe.fromCallable(new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  throw new UnsupportedOperationException();
              }
          })
              .test()
              .assertFailure(UnsupportedOperationException.class);
      }
  
      @SuppressWarnings("unchecked")
      @Test
      public void callable() throws Exception {
          final int[] counter = { 0 };
  
          Maybe<Integer> m = Maybe.fromCallable(new Callable<Integer>() {
              @Override
              public Integer call() throws Exception {
                  counter[0]++;
                  return 0;
              }
          });
  
          assertTrue(m.getClass().toString(), m instanceof Callable);
  
          assertEquals(0, ((Callable<Void>)m).call());
  
          assertEquals(1, counter[0]);
      }
  
      @Test
      public void noErrorLoss() throws Exception {
          List<Throwable> errors = TestCommonHelper.trackPluginErrors();
          try {
              final CountDownLatch cdl1 = new CountDownLatch(1);
              final CountDownLatch cdl2 = new CountDownLatch(1);
  
              TestObserver<Integer> to = Maybe.fromCallable(new Callable<Integer>() {
                  @Override
                  public Integer call() throws Exception {
                      cdl1.countDown();
                      cdl2.await();
                      return 1;
                  }
              }).subscribeOn(Schedulers.single()).test();
  
              assertTrue(cdl1.await(5, TimeUnit.SECONDS));
  
              to.cancel();
  
              cdl2.countDown();
  
              int timeout = 10;
  
              while (timeout-- > 0 && errors.isEmpty()) {
                  Thread.sleep(100);
              }
  
              TestCommonHelper.assertUndeliverable(errors, 0, InterruptedException.class);
          } finally {
              RxJavaCommonPlugins.reset();
          }
      }
  }
  